fwp-calendar/src/fwp-calendar.php

<?php
/**
 * Plugin Name: Free WordPress Calendar
 * Plugin URI: https://repobase.net/free-wordpress/fwp-calendar/
 * Description: Display multiple iCal feeds in a calendar and show upcoming events with a shortcode.
 * Version: 0.0.1
 * Author: Jacob Brown
 * License: GPL2
 * Text Domain: fwp-calendar
 */

require_once plugin_dir_path(__FILE__) . 'ical/ical.php';
require_once plugin_dir_path(__FILE__) . 'ical/event.php';

use ICal\ICal;

class FWP_Calendar {

    private $option_name = 'fwp_calendar_urls';

    public function __construct() {
        add_action('admin_menu', [$this, 'admin_menu']);
        add_action('admin_init', [$this, 'register_settings']);
        add_action('wp_enqueue_scripts', [$this, 'enqueue_assets']);
        add_shortcode('event-calendar', [$this, 'shortcode_handler']);
    }

    public function admin_menu() {
        add_options_page('FWP Calendar', 'FWP Calendar', 'manage_options', 'fwp-calendar', [$this, 'settings_page']);
    }

    public function register_settings() {
        register_setting('fwp-calendar-settings-group', $this->option_name);
    }

    public function enqueue_assets() {
        // Enqueue FullCalendar JS and CSS from plugin folder (ensure these files exist)
        wp_enqueue_script(
            'fwp-calendar-fullcalendar-js',
            plugins_url('fullcalendar.min.js', __FILE__),
            [],
            '6.1.8',
            true
        );

        wp_enqueue_script(
            'fwp-calendar-js',
            plugins_url('calendar.js', __FILE__),
            ['fwp-calendar-fullcalendar-js'],
            false,
            true
        );
    }

    public function settings_page() {
        ?>
        <div class="wrap">
            <h1>Free WordPress Calendar Settings</h1>
            <form method="post" action="options.php">
                <?php
                settings_fields('fwp-calendar-settings-group');
                $urls = get_option($this->option_name, []);
                if (!is_array($urls)) {
                    $urls = array_filter(array_map('trim', explode("\n", $urls)));
                }
                ?>
                <table class="form-table">
                    <tr valign="top">
                        <th scope="row">iCal URLs</th>
                        <td>
                            <div id="fwp-calendar-url-list">
                                <?php foreach ($urls as $i => $url): ?>
                                    <div class="fwp-url-entry" style="margin-bottom: 5px;">
                                        <input type="text" name="<?php echo esc_attr($this->option_name); ?>[]" value="<?php echo esc_attr($url); ?>" style="width: 90%;" />
                                        <button type="button" class="button button-small" onclick="this.parentNode.remove()">Remove</button>
                                    </div>
                                <?php endforeach; ?>
                            </div>
                            <button type="button" class="button" onclick="fwpAddUrlField()">Add URL</button>
                        </td>
                    </tr>
                </table>
                <?php submit_button(); ?>
            </form>
        </div>
        <script>
            function fwpAddUrlField() {
                const container = document.getElementById('fwp-calendar-url-list');
                const wrapper = document.createElement('div');
                wrapper.className = 'fwp-url-entry';
                wrapper.style = 'margin-bottom: 5px;';
                wrapper.innerHTML = `
                    <input type="text" name="<?php echo esc_attr($this->option_name); ?>[]" style="width: 90%;" />
                    <button type="button" class="button button-small" onclick="this.parentNode.remove()">Remove</button>
                `;
                container.appendChild(wrapper);
            }
        </script>
        <?php
    }


    public function shortcode_handler($atts) {
        $atts = shortcode_atts([
            'id' => '',
            'show_upcoming' => 'true',
        ], $atts);

        $show_upcoming = filter_var($atts['show_upcoming'], FILTER_VALIDATE_BOOLEAN);
        $urls = get_option($this->option_name, []);
        if (!is_array($urls)) $urls = [];

        if ($atts['id'] !== '') {
            $key = intval($atts['id']) - 1;
            if (isset($urls[$key])) {
                $urls = [$urls[$key]];
            } else {
                return '<p>Invalid calendar ID.</p>';
            }
        }

        $events = [];
        foreach ($urls as $url) {
            $url = trim($url);
            $ics_content = @file_get_contents(trim($url));

            if (!$ics_content) {
                error_log("FWP Calendar: Failed to fetch ICS from $url");
                continue;
            }
        
            try {
                $parser = new ICal();
                $parser->initString($ics_content);  // <-- This is the fix
            } catch (Exception $e) {
                error_log('FWP Calendar: Failed to parse ICS: ' . $e->getMessage());
                continue;
            }
        
            foreach ($parser->events() as $event) {
                $start_ts = method_exists($parser, 'iCalDateToTimestamp') 
                    ? $parser->iCalDateToTimestamp($event->dtstart) 
                    : strtotime($event->dtstart);
                $end_ts = isset($event->dtend) 
                    ? (method_exists($parser, 'iCalDateToTimestamp') ? $parser->iCalDateToTimestamp($event->dtend) : strtotime($event->dtend)) 
                    : $start_ts;
        
                $events[] = [
                    'title' => $event->summary ?? 'No Title',
                    'start' => date('c', $start_ts),
                    'end' => date('c', $end_ts),
                    'url' => $event->url ?? '',
                ];
            }
        }
        

        ob_start();
        ?>
        <div id="event-calendar" style="max-width: 900px; margin: auto; height: 600px;"></div>
        <script>
            var EventCalendar = {
                events: <?php echo json_encode($events); ?>
            };
        </script>
        <?php

        if ($show_upcoming && !empty($events)) {
            usort($events, function ($a, $b) {
                return strtotime($a['start']) - strtotime($b['start']);
            });
        
            $now = time();
            $count = 0;
        
            echo '<div class="upcoming-events" style="max-width: 900px; margin: 2rem auto;">';
            echo '<h2>Upcoming Events</h2><ul>';
        
            foreach ($events as $event) {
                $start_ts = strtotime($event['start']);
                if ($start_ts >= $now) {
                    $start_attr = esc_attr($event['start']);
                    $end_attr = isset($event['end']) ? esc_attr($event['end']) : '';
        
                    echo '<li class="event-item" data-title="'.$event['title'].'" data-start="' . $start_attr . '"';
                    if ($end_attr !== '') {
                        echo ' data-end="' . $end_attr . '"';
                    }
                    echo '>';
        
                    if (!empty($event['url'])) {
                        echo '<a href="' . esc_url($event['url']) . '" target="_blank" rel="noopener noreferrer">' . esc_html($event['title']) . '</a>';
                    } else {
                        echo esc_html($event['title']);
                    }
        
                    echo '</li>';
        
                    $count++;
                    if ($count >= 5) break;
                }
            }
        
            echo '</ul></div>';
        }


        return ob_get_clean();
    }
}

new FWP_Calendar();